The Malecon is beautiful anytime of day. It's calm & peaceful throughout the day and lively and densely populated in the evening. I love everything about La Paz. It's definitely one of my favorite destinations to escape to.
Relaxing and with a chill vibe you can walk my absolute favorite was watching the sunset. It is very kid friendly and has several playgrounds. Throughout the Malecón there are several restaurants, skate/bike park, shops, and ice cream.